Colletotrichum coccodes . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Colletotrichum coccodes . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Lycopersicon esculentum, Solanum tuberosum and over 35 other hosts, representing 13 families chiefly in the Cucurbitaceae, Leguminosae and Solanaceae (Cheaters & Hornby, 1965). Also on onion and strawberry on inoculation (36: 45). DISEASES: Black dot of potato and tomato, anthracnose of fruits of tomato, chilli ( Capsicum ) and squash. Causes a distinctive cortical brown rot of stems and roots of potato and tomato, chilli, eggplant and winter cherry ( Solanum capsicastrum ). The roots of other less susceptible hosts including chrysanthemum, white mustard, cress, cabbage, and lettuce are only lightly colonized, and the infected plants may be symptomless. Commonly causes destruction of cortical tissues of stems and roots of hosts, also fruit rot of tomato. On potato, black dot on stem root, and tuber, sometimes associated with leaf scorch (31: 574), skin necrosis (38: 621), rubbery tuber wilt (41: 670) and spindle sprout (35: 540, 918). Enzymes secreted by the pathogen are responsible for foot and root rot stages; wilting of aerial organs is a remote effect of operation of toxins (35: 541). GEOGRAPHICAL DISTRIBUTION: Widely distributed in Africa, Asia, Australasia, Europe, and N., C., and S. America. (CMI Map l90) TRANSMISSION: Soil borne, but no rapid or extensive growth of hyphae through soil; survival probably only in decaying roots and other trash and on weed hosts. Infection occurs when living roots grow in contact with organic material harbouring the pathogen (32: 608; 36: 502, 719). Sclerotia overwinter on trash and develop into acervuli in spring (38: 478); they survive up to 84 wks. in greenhouse soil (45, 3066). In potato, transmission is from infected plants through the daughter tubers, and incidence of infection increases during storage; new plants are infected from dead material by conidia (35: 541; 34: 480). Persistence on weeds such as Solanum dulcamara and S. nigrum maybe implicated in carry-over from potato to tomato crops (45, 1204).